Modelling, scale-up and techno-economic assessment of rotating packed bed absorber for CO2 capture from a 250 MWe combined cycle gas turbine power plant
Olajide Otitoju, Eni Oko, Meihong Wang
Abstract
The huge sizes and costs of the packed bed (PB) absorbers and strippers in solvent-based post-combustion carbon capture are part of the challenges limiting its commercialization. The rotating packed bed (RPB) absorbers and strippers have the potential to reduce the size and cost of the CO2 capture process when used to replace their PB counterparts. However, the size and cost have not been quantified for a large-scale RPB. Therefore, this paper is devoted to providing detailed technical and economic assessments of a large-scale RPB absorber operated with concentrated (55-75 wt%) monoethanoamine (MEA). To achieve this, a steady-state rate-based model of the RPB absorber was developed and validated in Aspen Custom Modeller®. The model was scaled up to capture CO2 from the flue gas of a 250 MWe CCGT power plant using an iterative scale-up methodology proposed in this study. Technical assessments of the large-scale RPB absorber indicated that a 4–11 times volume reduction factor was achieved with 55 wt% MEA concentration compared to PB absorbers. The highest volume reduction factors of 5–13 times were achieved in RPB absorber operated with 75 wt% MEA. Economic assessments show that the capital expenditures of the RPB absorbers were lower by 3–53%. The CO2 capture cost was also lower ($6.5/tCO2–$9/tCO2) compared to $15/tCO2–$24/tCO2 obtained for the PB absorbers.